Protecting the skin from damage due to ultraviolet rays is an important object in skin care and body care, and various UV-care cosmetics for minimizing the harmful effects of ultraviolet rays on the skin have been developed. Sunscreen cosmetics, which are a type of UV-care cosmetic, are cosmetics that are intended to protect the skin from damage due to ultraviolet rays, by covering the skin with a coating that contains an ultraviolet ray absorbing agent or an ultraviolet ray scattering agent, thereby absorbing or scattering UVA and UVB rays, and limiting the amount of ultraviolet rays that reach the skin (Non-Patent Document 1).
Ethylhexyl methoxycinnamate and octocrylene (2-ethylhexyl 2-cyano-3,3-diphenylprop-2-enoate) have been generally used in conventional sunscreen cosmetics, as liquid ultraviolet ray absorbing agents having absorption wavelengths primarily in the UVB range. However, these ultraviolet ray absorbing agents can sometimes irritate the skin of users with sensitive skin, and for example, a skin-care preparation for external use in which irritation due to ethylhexyl methoxycinnamate is mitigated by adding polypropylene glycol dimethyl ether has been proposed (Patent Document 1).
Patent Document 2 discloses a so-called non-chemical sunscreen cosmetic that does not contain ethylhexyl methoxycinnamate, octocrylene or avobenzone, but instead contains a combination of multiple powder ingredients that have an ultraviolet ray scattering effect, and the cosmetic does not irritate the eyes even when applied to the face. However, it is necessary to add a large quantity of powder ingredients in order to obtain high ultraviolet ray protection effects (high SPF) using only powder ingredients, and in some cases, an unnatural whiteness can occur when applied to the skin.
On the other hand, most organic ultraviolet ray absorbing agents other than ethylhexyl methoxycinnamate and octocrylene are solid at ambient temperature. In conventional sunscreen cosmetics, liquid ethylhexyl methoxycinnamate and octocrylene also served the function of solvents, so there were no problems. However, if the blended amounts of these liquid ultraviolet ray absorbing agents are reduced, the co-blended solid ultraviolet ray absorbing agents can sometimes precipitate out, and if the blended amounts of the solvents (oils) used for the solid ultraviolet ray absorbing agents are increased in order to prevent precipitation, then the blending ratio of the ultraviolet ray absorbing agents relative to the entire cosmetic decreases, so that sufficient ultraviolet ray protection effects cannot be obtained, and raising concerns regarding problems in the texture, such as stickiness being caused by the oils.